package com.newcoder.huawei;

import java.util.Scanner;
import java.util.Set;
import java.util.TreeSet;

/**
 * 字符个数统计
 */
public class HJ10 {

    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        Set charSet =  new TreeSet();
        while (in.hasNext()) {
            String inputLine = in.nextLine();
            inputLine = inputLine.replace(" ", "");
            char[] charArray = inputLine.toCharArray();
            for (int i = 0; i < charArray.length; i++) {
                charSet.add(charArray[i]);
            }
        }
        System.out.println(charSet.size());
    }
}
